Simulate an FMU

The Otfmi simulate function instanciates, initializes and simulates the FMU.

First, retrieve and load the FMU deviation.fmu.

import openturns as ot
import otfmi.example.utility
import matplotlib.pyplot as plt

path_fmu = otfmi.example.utility.get_path_fmu("deviation")
model = otfmi.fmi.load_fmu(path_fmu)

Note

model is a PyFMI object, loaded with Otfmi’s overlay.

As such, model.simulate() is a pure PyFMI method.

Use otfmi.fmi.simulate(model) to benefit from Otfmi’s overlay.

Otfmi simulate function notably eases initializing a FMU, see Initialize an FMU with non-default values.

On top of the initialization keywords, PyFMI simulation keywords can be employed:

result = otfmi.fmi.simulate(
    model,
    start_time=0,  # PyFMI keyword
    final_time=1,  # PyFMI keyword
    initialization_parameters=(["L"], [300]),
)  # Otfmi keyword
print("y = %g" % result.final("y"))

Simulation interval    : 0 - 1.0 seconds.
Elapsed simulation time: 0.011409133000029215 seconds.
y = 22.5

We can use these keyword to plot the deviation Y as function of the beam length L:

inputSample = ot.RegularGrid(1.0, 10.0, 10).getValues()

list_output = []
for length in inputSample:
    result = otfmi.fmi.simulate(model, initialization_parameters=(["L"], [length]))
    list_output.append(result.final("y"))
outputSample = ot.Sample([[xx] for xx in list_output])

plt.figure()
plt.plot(inputSample, outputSample)
plt.show()

Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.011713799999995445 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.011339383000006364 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.011396659000013187 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.011423528999955579 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.011411737000003086 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.011422046000006958 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.011402511000028426 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.011396627999999964 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.01136045200001945 seconds.
Simulation interval    : 0.0 - 1.0 seconds.
Elapsed simulation time: 0.011462139999991905 seconds.

The interest of the higher-level functions are:

- avoid the for loop on the points of the design of experiment,

- automatic formatting of the simulation outputs.